Shields for preventing the leak and intrusion of electromagnetic waves are used in electronic and communications apparatuses such as cell phones, personal computers, etc. Shields widely used at present are metal sheets or nets, etc., but they are heavy and bulky, and not easy to be disposed in apparatus casings. As a light-weight, electromagnetic-wave-absorbing shield, which can be easily disposed in plastic casings, etc., JP 9-148782 A proposes a shield comprises a first aluminum film vapor-deposited on one surface of a plastic film and etched to have a non-conductive linear pattern, and a second aluminum film vapor-deposited on the other surface of the plastic film and etched to have a network pattern. However, the linear patterns and the network patterns illustrated in this reference are all periodic, absorbing only electromagnetic waves in particular frequencies, but failing to absorb electromagnetic waves in a wide frequency range without leak. In addition, because the patterns are obtained by etching, this electromagnetic-wave-absorbing shield is inevitably expensive.
JP 11-40980 A proposes an electromagnetic wave shield having a copper layer and a nickel layer both vapor-deposited on one surface of a plastic film. However, this electromagnetic wave shield does not have linear gaps in the vapor-deposited layer, exhibiting low electromagnetic wave absorbability.